1. Field of the Invention
The present invention relates to an image forming apparatus capable of offset stacking each set of output paper sheets to be post-processed in the same batch by a nearline or offline post processing apparatus, a method for controlling the image forming apparatus, and a storage medium with a program and/or computer-executable instructions for executing the method for controlling the image forming apparatus.
2. Description of the Related Art
In general, to obtain printouts, after a printing apparatus completes printing, an operator delivers a set of printed paper sheets to a post-processing apparatus (i.e., a finisher) installed at a location remote from the printing apparatus, where the post-processing apparatus performs post-processing.
In addition, when a printing apparatus prints a plurality of copies of a document, the printing apparatus can offset stack each of the copies of the document so that an operator can readily distinguish the different sets of copies.
Furthermore, in order to separate printed sheets of paper into several sets, Japanese Patent Laid-Open No. 2001-30584 describes a technology for separating a print job into sub-jobs so that the number of sheets of a sub-job does not exceed the maximum number of sheets defined by an inline booklet finisher.
However, in the above-described existing technology, offset stacking in accordance with a set of printed sheets to be post-processed by the downstream nearline or offline post-processing apparatus cannot be achieved. Accordingly, an operator may be required to manually separate the sets of printed sheets before placing the set of sheets in the post-processing apparatus. Alternatively, an operator may be required to compute the number of sheets corresponding to the set of sheets to be post-processed and input the number of sheets for offset stacking to an operation unit of the printing apparatus. In order to perform these operations, the operator may need to learn how to operate the post-processing apparatus or set an appropriate setting in the printing apparatus.
In such a case, by using the technology described in Japanese Patent Laid-Open No. 2001-30584, the job can be separated into sub-jobs so that the number of sheets of a sub-job does not exceed the maximum number of sheets defined by an inline booklet finisher. However, this technology does not take into account the processing performed by the downstream nearline or offline post-processing apparatus remote from the printing apparatus. Therefore, a separating operation performed by an operator may still be needed.